Rectifying system for aluminum-cell lightning-arresters.



O. P. STEINMETZ. REGTIPYING SYSTEM FOR ALUMINUM CELL LIGHTNINGARRESTERS.

APPLICATION FILED SEPT.13 1910.

Patented Mar. 28, 1911.

Inventor: Charles P Steinmetz Witnesses:

l-Iisflttorngg UNITED STATES PATENT oFFIoa;

CHARLES r. s'rrmmnrz, orscnnnnc'rany, new loan, sssrenoa T0 GENERALELECTRIC COMPANY, :A GOBPORATION OFNEW YORK.

BDG'IIFYING SYSTEM F03 ALUHiNUMdEIL LIGHTNING-ABBESTERS.

Specification 0t Letters Patent.

Patented Mar. 28, 1911.

implication 11l6d Septemher 13, 1910. Serial No. 531 840.

To allwhom, it may concern: 4

Be it known that 1, CHARLES P. STEIN- ivlnrz, a citizen of the UnitedStates, residmg at Schenectady, county of Schenectady, State of NewYork, have invented certain new and useful Improvements in Rectifying yt m A umin m-Cell Lig g-A :esters, of which the following is aspecificamn. v This invention relates to electrolytic condensors, andparticularly to electrolytic lightningv arresters of the aluminum cellty e. gt has been found that when a lightning arrester of the'alumiuumcell type is sub.- ected to an alternating current it rapidlydeteriorates, whereas, if the current be direct or Epulsating thearrcster lasts much longer, an therefore it has been proposed to combinewith a lightning arrester of this type some suitable mechanicalrectifying appara u aluminum cells a pulsating unidirectional currentinstead of the alternating current of the line. For some purposes someother 'type of rectifier is better than a mechanical rectifier, and theobject of the present invention is to permit some type ofrectifielwith-.

out moving parts, such for instance as a mercury arc rectifier, tobeusedto impress the desired unidirectional voltage on the cell. so thattroubles incident to moving mechanism and the nice regulation requiredto keep said mechanism in phase with the alternating current areovercome.

'In the accompanying drawing, in which some of the var ous forms inwhich the invention may be embodied are shown merely to illustrate theinvention, Figure 1 is a diagram showing the combination of a mercuryarc rectifier with an aluminum cell lightning arrester; Fig. 2 is adiagram of a similar system including 'a/spark gap in series with thearrester, and Fig. 3 is a dia-' gram of a system similar to Fig. 1, butshowing a difierent kind'of aluminum cell.

The lightning arrester shown in Figs. 1 and 2 consists of a number ofaluminum cups nested together and having somesuitable electrolyte in thecups. The upper cup is connectedto line at "2, and the lower cup isgrounded at 3. If the alternating potential of the line is impresseddirectly upon such an arrester there will be a certain leakfor thepurpose of supplying to the age discharge through the arrester whichheats the electrolyte excessively, and in a few hours causes it to boil,a condition which soon causes the destruction of this type of aluminumcell. A pulsating unidirectional current, on the other hand, haspractically no destructive effect when it flows through the cells,-andtherefore, gives "a long life to the cells. 'Toobtain such a odes 10 and11 connected to a suitable source of power, such as the secondary coilof a transformer 12 whose middle point is connected through thereactances 13 and 9 to the cathode 8. Y

With the circuit connections shown a unidirectional'voltage is impressedupon the arrester between the middle of the two ends, and issuperimposed on the alternating voltage impressed upon the arrester bythe line, so that the resultant voltages on the two halves of thearrester are unidirectional pulsating voltages, and consequently apulsating unidirectional current flows through half the cells at eachpositive wave of the alternating line current, and a similarunidirectional current flows through the other half of the cells at eachnegative wave. A discharge of lightning will'pass readily through thearrester. but is efiectuallykept out of-the recs tifier by thereactances 7. l p In Fig. 2 I have shown a spark gap 14 in series withthe arrester with the rectifier connected in shunt td said gap as wellas to the arrester. The gap, however, is readily jumped by lightning,which passes off by way of the arrester, as in the arrangement shown inFig. 1. V 1

Fig. 3 illustrates the application of the mercury rectifier to adifferent kind of electrolytic lightning arrester. The cells 15 are jarsof glass or the like filled with a suitable electrolyte in whichthealuminum electrodes ode lead 17 is connected in between the twomiddle cells of said battery, and as in the arrangement shown in Fig. 1,the unidirectional current in this lead flows through onehalf of thebattery duringythe ositive wave and then through the other ha i duringthe negative wave of the alternating line current. p

The employmentof a mercury arc-rectifier results in a erfectly automaticsupply of pulsating uni irectional current through the battery withoutany necessity of that careful adjustment and oversight to insure exactphase relations which is called for by mechanical rectifiers.

The device is not thrown out of operation by a change in frequency ofthe line current, and consumes an amount of energy which is small, butis sufiicient to keep the films in good resistant condition.

Although I have describedthe principle of operation of my inventiontogether with the apparatus which I now consider to represent the bestembodiment thereof, I desire to have it understood that the apparatusshown is only illustrative and that the invention can be carried out byother means; and that I intend to cover by the appended claims allchanges and modifications within the scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is 1. The combination with an electrolytic lightning arrester foran alternating current system, of a mercury arc rectifier connected toderive a unidirectional potential from said system and to impress it onsaid arrester.

2. The combination with an electrolytic lightning arrester for analternating current system, of avapor rectifier in shunt thereto forimpressinga unidirectional potential on said arrester.

3. The combination with an electrolytic lightning arrester for analternating current system, of a vapor rectifier having its anodesconnected to the terminals-of said arrester,

and its cathode connected to an intermediate point in said 'arrester.

4. The combination with an electrolytic lightning arrester for analternating current system, of a mercury rectifier having its anodesconnected to the terminals of said arrester and its cathode connectedtoan intermediate point in said arrester, and reactances interposedbetween said rectifier and the arrester terminals.

5. The combination with an electrolytic lightning arrester for analternating current system,'of a spark ap in series with said arrester,and a recti er in shunt to said gap and arrester for impressing aunidirectional potential on said arrester.

6. The combination with an alternating current system, of electrodesseparated by electrolyte and connected to said system, and means forcombining with the altemating potential of said system a unidirectionalpotential to maintain between said electrodes a unidirectional resultantpotential.

In. witness whereof, I have hereunto set my hand this 12th day ofSeptember,;1910.

CHARLES P. STEINMETZ.

Witnesses:

BENJAMIN B. HULL, HELEN Omronn.

